Cooperation robot for vehicle production system and method for controlling the same

ABSTRACT

A cooperation robot for moving a bumper to a predetermined position of a vehicle in a vehicle production system includes: a multi-axis arm, a front end portion of which is connected to and a rear end portion of which is connected to a robot body so that the multi-axis arm is movably disposed to upper, lower, left and right sides on the basis of the robot body. The multi-axis arm is disposed to rotate the gripper. A force torque (FT) sensor is disposed between the multi-axis arm and the gripper and detects a direction of external force which is applied to the gripper and the bumper gripped by the gripper. An operator controls the multi-axis arm so that positions of the gripper and the bumper vary. A controller controls the operator according to the direction of the external force detected by the FT sensor when the multi-axis arm is in a stand-by condition to move the gripper in the direction the external force.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to Korean PatentApplication No. 10-2015-0170995 filed in the Korean IntellectualProperty Office on Dec. 2, 2015, the entire content of which isincorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to a cooperation robot for a vehicleproduction system. More particularly, the present disclosure relates toa cooperation robot for a vehicle production system and a method forcontrolling the cooperation robot for the vehicle production system,capable of gripping a bumper, moving a vehicle body to a predeterminedposition, and easily mounting the bumper on the vehicle body.

BACKGROUND

In the industry manufacturing field, a cooperation robot has been usedfor simple repetitive and hard operation which brings musculoskeletalinjury to workers.

During the vehicle assembly, a process of mounting a trunk lead hinge ona vehicle body needs repetitive operation, and thus, places stresses toa wrist of the worker. To lessen this problem, energy saving equipmentof weight balance type has been used.

However, load of the worker increases during engaging the trunk leadhinge because it is difficult to control exact position of this energysaving equipment, and it is difficult to apply the energy savingequipment to various types of vehicles.

Accordingly, researches related to intelligent energy saving loaderhaving worker's delicacy and robot's obdurability have been undertaken.By these researches, labor load and field danger are lessen, effect ofcommonly applying to various vehicles is expected.

The above information disclosed in this Background section is only forenhancement of understanding of the background of the invention, andtherefore, it may contain information that does not form the prior artthat is already known in this country to a person of ordinary skill inthe art.

SUMMARY

An aspect of the present disclosure provides a cooperation robot for avehicle production system, capable of improving efficiency ofmanufacturing system by providing the cooperation robot assisting aworker and by combining intelligence and delicacy of human and improvingdurability and control performance of the robot.

A cooperation robot for moving a bumper to a predetermined position of avehicle in vehicle production system according to an exemplaryembodiment in the present disclosure may include a multi-axis arm, afront end portion of which is connected to a gripper for gripping thebumper and a rear end portion of which is connected to a robot body, sothat the multi-axis arm is disposed movably to upper, lower, left andright sides of the robot body. The robot body rotates the gripper Aforce torque (FT) sensor is disposed between the multi-axis arm and thegripper and detects a direction of external force that is applied to thegripper and the bumper gripped by the gripper. An operator controls themulti-axis arm so that a position of the gripper and the bumper varies.A controller controls the operator according to the direction of theexternal force detected by the FT sensor when the multi-axis arm is in astand-by condition to move the gripper in the direction of the externalforce.

The cooperation robot may further includes a gravity compensationapparatus mounted on an opposite side of the multi-axis arm on the basisof the robot body, and decreasing rotational torque applied to the robotbody by the multi-axis arm by moving weight becoming close to or farfrom the robot body.

The operator may include a motor providing torque moving the gripper toa predetermined route in three-dimensional space by moving themulti-axis arm along a predetermined axis or rotating the multi-axis armaround the axis.

The controller detects a reference rotation position and an actualrotation position of the motor and decides whether collision is occurredaccording to the reference rotation position and the actual rotationposition, and if it is decided that collision is occurred, operation ofthe motor may be stopped.

The cooperation robot further may include a neighboring sensor disposedon a side of the multi-axis arm and detecting an object in apredetermined distance region, and the controller stops operation ofmulti-axis arm if the object is detected by the neighboring sensor.

The gravity compensation apparatus may include an arm rotation portionrotating together according to moving to upper and lower sides of themulti-axis arm, a pushing arm a side is disposed to rotate according tothe arm rotation portion and other side is disposed to push the weightaway from the robot body, and an elastic member elastically supportingthe weight toward the robot body.

The cooperation robot may include a fixing bracket fixed on the robotbody by a predetermined interval with the weight, and a guide rodextending to opposite side of the robot body from the weight anddisposed to penetrate the fixing bracket, and the elastic member may beinterposed between the fixing bracket and the weight in a compressedstate.

The elastic member may be a coil-spring type rolled up along acircumference of the guide rod, a side portion of the elastic member maybe supported by the fixing bracket, and another side of the elasticmember is disposed to push the weight.

A method for controlling a cooperation robot of a vehicle productionsystem according to an exemplary embodiment in the present disclosureincludes gripping a bumper using a gripper disposed on a front endportion of a multi-axis arm, moving the bumper to a predeterminedposition of the vehicle by operating the multi-axis arm, detectingdirection of external force applied to the bumper of the gripper by aforce torque (FT) sensor while the multi-axis arm is stopped, andadjusting a position of the bumper disposed on the gripper by operatingthe multi-axis arm according to the direction of the external force.

The position of the gripper may be controlled in three-dimensional spaceby operating the multi-axis arm by using a motor and a deceleratinggear, a reference rotation position and an actual rotation position ofthe motor are detected, and it is decided whether collision is occurredaccording to difference between the reference rotation position and theactual rotation position, and if it is decided that the collision isoccurred, the operation of the motor may be stopped.

When it is decided that an object is detected at a neighboring sensordisposed on a side of the multi-axis arm and detecting an object in apredetermined distance, operation of the multi-axis arm may be stopped.

The gripper is mounted on a front end portion of the multi-axis arm, anda robot body is disposed on a rear end portion, and the method mayinclude decreasing rotational torque applied to the robot body by themulti-axis arm by moving weight becoming close to or far from the robotbody, the weight is disposed on opposite side of the multi-axis arm onthe basis of the robot body according to upper and lower position of themulti-axis arm.

The FT sensor may be disposed on a part connecting the multi-axis armand the gripper.

According to the present invention for accomplishing the purpose these,operator's delicacy and robot's obdurability may be provided at the sametime by moving a bumper to a predetermined position by using acooperation robot, detecting direction of force applied to thecooperation robot by an FT sensor, and precisely adjusting a position ofa multi-axis arm to the detected direction of the force.

Further, stability may be improved by detecting operators or objects byneighboring sensor to stop movement of the multi-axis arm.

Further, operational stability and precision of the entire cooperationrobot may be improved by preventing shaking of the multi-axis arm byusing a gravity compensation apparatus.

Further, in case of detecting collision by using rotational position ofa motor operating the multi-axis arm, more stable production system maybe provided by stopping operation of the multi-axis arm.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram of a cooperation robot for a vehicleproduction system according to an exemplary embodiment in the presentdisclosure.

FIG. 2 is a partial perspective view of a cooperation robot for avehicle production system according to an exemplary embodiment in thepresent disclosure.

FIG. 3 is an entire perspective view of a cooperation robot according toan exemplary embodiment in the present disclosure.

FIG. 4 is a partial perspective view of a cooperation robot and agravity compensation apparatus according to an exemplary embodiment inthe present disclosure.

FIG. 5 is a partial side view illustrating operation state of a gravitycompensation apparatus mounted on a cooperation robot according to anexemplary embodiment in the present disclosure.

FIG. 6 is a flowchart illustrating a method for controlling acooperation robot of a vehicle production system according to anexemplary embodiment in the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

An exemplary embodiment in the present disclosure will hereinafter bedescribed in detail with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of a cooperation robot for a vehicleproduction system according to an exemplary embodiment in the presentdisclosure.

Referring to FIG. 1, a cooperation robot for a vehicle production systemincludes a bumper 100, a vehicle body 110, and a cooperation robot 120,and the cooperation robot 120 includes a multi-axis arm 124, a gripper200, a gravity compensation apparatus 130, a force torque (FT) sensor122, a neighboring sensor 126, an operator 128, and a controller 140.

The gripper 200 is mounted on an end portion of the multi-axis arm 124,the operator 128 varies a position and a rotational position of thegripper 200 by the multi-axis arm 124 in three-dimensional space andgrips the bumper 100 by operating the gripper 200.

The FT sensor 122 detects a direction of external force and strength ofthe gripper 200 or the bumper 100 gripped by the gripper 200, and thecontroller 140 may control the multi-axis arm 124 according to theexternal force and strength detected by the FT sensor 122 to control aprecise position of the bumper 100.

The neighboring sensor 126 detects objects or workers surrounding themulti-axis arm 124 or the gripper 200 and transmits the detected signalto the controller 140, and the controller 140 stops operation ofmulti-axis arm 124 and the gripper 200 using detection signaltransmitted at the neighboring sensor 126.

According to an exemplary embodiment of the present invention, thegravity compensation apparatus 130 is described afterwards by referringFIG. 4 and FIG. 5, and the controller 140 may be realized by at leastone microprocessor operating by a predetermined program, and thepredetermined program may include a series of orders for conductingmethod according to the present disclosure.

FIG. 2 is a partial perspective view of a cooperation robot for avehicle production system according to an exemplary embodiment in thepresent disclosure.

Referring to FIG. 2, the gripper 200 is mounted on an end portion of themulti-axis arm 124, and the gripper 200 controls a position of an upperfinger 204 and a lower finger 202 to grip center upper and lower partsof the bumper 100 and to move to the front of the vehicle body 110.

The operator 128 includes a motor and decelerator and controls operationof the multi-axis arm 124 and the gripper 200 by using rotational forceof the motor, and the controller 140 detects an actual rotation positionof the motor and detects external collision by using a difference valuebetween the actual rotation position and a theoretical rotation positionto stop the operation of the motor and to stop the operation of themulti-axis arm 124 and the gripper 200.

That is, when impact is applied to the multi-axis arm 124, the gripper200 or the bumper 100 by a worker or an external object, a rotationposition of the motor operating the multi-axis arm 124 or the gripper200 varies. If it is decided that the varied value is more than apredetermined value, the operator is stopped and additional collision orproblem may be prevented in advance.

According to an exemplary embodiment in the present disclosure, thestructure and principle of operating the multi-axis arm 124 and thegripper 200 by the motor and the decelerator are referred to well-knowntechnology, and therefore, a detailed description thereof will beomitted.

FIG. 3 is an entire perspective view of a cooperation robot according toan exemplary embodiment in the present disclosure.

Referring to FIG. 3, the cooperation robot 120 includes the gravitycompensation apparatus 130, the robot body 320, a first axis 300, theneighboring sensor 126, an arm body 302, a second axis 304, a third axis306, the FT sensor 122 and the gripper 200.

The first axis 300 is connected to the robot body 320 by a drive shaft,the arm body 302 is disposed at an end part of the first axis 300, thesecond axis 304 is connected to an end part of the arm body 302, thethird axis 306 is connected to an end part of the second axis 304, thegripper 200 is connected to an end part of the third axis 306, and theFT sensor 122 is disposed between the gripper 200 and the third axis306.

The robot body 320 rotates the first axis 300 to left and right sides,raises to upper side or lowers to a lower side, and the arm body 302moves to the upper or lower sides by the first axis 300.

In addition, the second axis 304 moves to the left and right sides bythe motor and the decelerator on the basis of the arm body 302, and thethird axis 306 moves to the left and right sides by the motor and thedecelerator on the basis of the second axis 304.

According to the present disclosure, the gripper 200 may include theupper finger 204 and the lower finger 202 which grip the upper part andthe lower part of the bumper 100 mounted on the vehicle body 110 and mayinclude a cylinder moving the upper finger 204 and the lower finger 202to the upper, lower, left and right sides. Here, the gripper 200 mayhave a structure rotating by the motor and the decelerator installed atthe third axis 306.

In addition, the neighboring sensor 126 is disposed on a front surfaceof the arm body 302 and detects surrounding objects or workers totransmit signal to the controller 140. Further, the controller 140 maystop movement of the multi-axis arm 124 to prevent collision of themulti-axis arm 124 of the cooperation robot 120 with the objects orworkers in advance by the signal transmitted from the neighboring sensor126. In addition, the neighboring sensor 126 is mounted on the frontsurface of the arm body 302, or may be mounted on a predeterminedposition of the multi-axis arm.

FIG. 4 is a partial perspective view of a cooperation robot and agravity compensation apparatus according to an exemplary embodiment inthe present disclosure.

Referring to FIG. 4, the gravity compensation apparatus 130 is disposedon an opposite side of the multi-axis arm 124 on the basis of the robotbody 320. The gravity compensation apparatus 130 includes an armrotation portion 400, a torque transfer portion 405, a pushing arm 410,a roller 415, a weight 420, an elastic member 425, a fixing bracket 430and a guide rod 435.

When the first axis 300 rotates on the basis of the drive shaft (308 inFIG. 3), the arm rotation portion 400 rotates, and the arm rotationportion 400 rotates the pushing arm 410 through the torque transferportion 405 of a belt or a chain type.

Further, when the pushing arm 410 rotates, the roller 415 disposed on afront end of the pushing arm 410 compresses the elastic member 425 topush the weight 420. Here, the fixing bracket 430 is fixed on the robotbody 320, and the guide rod 435 guides movement of the weight 420.

FIG. 5 is a partial side view illustrating operation state of a gravitycompensation apparatus mounted on a cooperation robot according to anexemplary embodiment in the present disclosure.

Referring to FIG. 5, the guide rod 435 facing rearward of the weight 420is provided, and a front end portion of the guide rod 435 is disposedpenetrating the fixing bracket 430.

The elastic member 425 is a coil spring type and rolled along anexterior circumference, and one end part of the elastic member 425supports elastically the weight 420 to a side of the multi-axis arm 124and another end part is supported elastically at the fixing bracket 430.

In addition, the roller 415 pushes the weight 420 to the opposite sideof the multi-axis arm 124 according to a rotation position of thepushing arm 410, and the elastic member 425 pushes the weight 420 to theside of the multi-axis arm 124 in the state which the roller 415 doesnot push the weight 420.

In the present disclosure, entire stability of operation of thecooperation robot and durability etc. may be improved and reduce shakingof the multi-axis arm 124 on the basis of the robot body 320 by pushingor puffing the weight 420 by the pushing arm 410 through the roller 415.A rotational torque applied to the robot body 320 is reduced by movementto the upper and lower direction of the multi-axis arm 124.

FIG. 6 is a flowchart illustrating a method for controlling acooperation robot of a vehicle production system according to anexemplary embodiment in the present disclosure.

Referring to FIG. 6, a control starts in S600, the bumper 100 isgripping by the gripper 200 in S605, and the bumper is transferred to apredetermined route in S610.

A logic detecting collision through a rotation position error of themotor in a process of transferring the bumper 100 by the gripper 200 andthe multi-axis arm 124 is performed in S615.

Here, an actual rotation position and a theoretical rotation position ofthe motor are compared, and the controller 140 may detect collisionaccording to the amount of difference value between them.

When the collision is detected in S615, an operation of the cooperationrobot 120 stops and transfer of the bumper 100 is stopped. Further, whenrelease button 600 is pushed by the worker, stop of the cooperationrobot 120 is released in S625, and S610 is performed again.

If the collision is not detected in S615, the bumper 100 is transferredto the predetermined position in S630, and the cooperation robot 120stands by in stopped state at the predetermined position of the bumper100 in S635.

The worker may provide external force to the gripper 200 or the bumper100 to adjust position of the bumper 100 in S640 and S645. Here, thecontroller 140 may precisely adjust the position of the bumper byoperating the multi-axis arm 124.

More specifically, the FT sensor 122 detects a direction and a forceapplied from the gripper 200 or the bumper 100 in S640 and transmit asignal to the controller 140, and the controller 140 controls themulti-axis arm 124 according to the direction and the force detected bythe FT sensor 122 to precisely adjust position of the bumper 100.

Next, when the worker pushes temporary complete button 605, it isdecided that temporary attachment of the bumper 100 is completed inS650, and the gripper 200 releases gripping of the bumper 100 and therobot returns to the initial position in S655.

Further, if it is decided that attachment of the bumper 100 is completedby the complete button 610 in S660, attachment mode of the bumper 100ends in S665, and S600 starts again.

While this invention has been described in connection with what ispresently considered to be practical exemplary embodiments, it is to beunderstood that the invention is not limited to the disclosedembodiments. On the contrary, it is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope of the appended claims.

What is claimed is:
 1. A cooperation robot for moving a bumper to apredetermined position of a vehicle in a vehicle production system, thecooperation robot comprising: a multi-axis arm, a front end portion ofwhich is connected to a gripper for gripping the bumper and a rear endportion of which is connected to a robot body, so that the multi-axisarm is movably disposed around upper, lower, left and right sides of therobot body and rotates the gripper; a force torque (FT) sensor disposedbetween the multi-axis arm and the gripper, the FT sensor detecting adirection of external force applied to the gripper and the bumper thatis gripped by the gripper; an operator controlling the multi-axis arm sothat a position of the gripper and the bumper, which is gripped by thegripper, varies; a controller controlling the operator according to thedirection of the external force detected by the FT sensor when themulti-axis arm is in a stand-by condition to move the gripper to in thedirection of the external force; and a neighboring sensor disposed on aside of the multi-axis arm and detecting an object in a predetermineddistance region; wherein the controller stops operation of themulti-axis arm if the object is detected by the neighboring sensor,wherein the multi-axis arm includes: a first axis having one end that isconnected to the robot body by a drive shaft; an arm body having one endthat is connected to another end of the first axis; a second axis havingone end connected to another end of the arm body; and a third axishaving one end, which is connected to another end of the second axis,and another end, which is connected to the gripper, wherein the FTsensor is disposed between the gripper and the third axis, and whereinthe neighboring sensor is disposed on a front surface of the arm body.2. The cooperation robot of claim 1, further comprising: a gravitycompensation apparatus mounted on an opposite side of the multi-axis armbased on the robot body and decreasing a rotational torque applied tothe robot body by the multi-axis arm by moving a weight toward or awayfrom the robot body.
 3. The cooperation robot of claim 1, wherein theoperator includes: a motor generating a torque to move the gripper to apredetermined route in a three-dimensional space by moving themulti-axis arm along a predetermined axis or rotating the multi-axis armaround the predetermined axis.
 4. The cooperation robot of claim 3,wherein the controller detects a reference rotation position and anactual rotation position of the motor and determines whether collisionoccurs according to a difference value between the reference rotationposition and the actual rotation position, and wherein when thecontroller determines that that collision occurs, the motor stopsoperating.
 5. The cooperation robot of claim 2, wherein the gravitycompensation apparatus includes: an arm rotation portion rotating as theupper and lower sides of the multi-axis arm move; a pushing arm, oneside of which rotates according to the arm rotation portion and anotherside of which is disposed to push the weight away from the robot body;and an elastic member elastically supporting the weight toward the robotbody.
 6. The cooperation robot of claim 5, further comprising: a fixingbracket fixed on the robot body by a predetermined interval with theweight; and a guide rod extending on the weight away from the robot bodyand penetrating the fixing bracket, wherein the elastic member isinterposed between the fixing bracket and the weight in a compressedstate.
 7. The cooperation robot of claim 6, wherein the elastic memberis a coil-spring that is rolled up along a circumference of the guiderod, wherein one side portion of the elastic member is supported by thefixing bracket and another side of the elastic member is disposed topush the weight.
 8. A method for controlling a cooperation robot of avehicle production system, comprising steps of: gripping a bumper usinga gripper which is disposed on a front end portion of a multi-axis arm;moving the bumper to a predetermined position of the vehicle byoperating the multi-axis arm; detecting a direction of external forceapplied to the bumper gripped by the gripper by a force torque (FT)sensor while the multi-axis arm is stopped; and adjusting a position ofthe bumper that is disposed on the gripper by operating the multi-axisarm according to the direction of the external force, wherein when anobject is detected at a neighboring sensor, which is disposed on a sideof the multi-axis arm, in a predetermined distance, the multi-axis armstops operating, wherein the multi-axis arm includes: a first axishaving one end that is connected to the robot body by a drive shaft; anarm body having one end that is connected to another end of the firstaxis; a second axis having one end connected to another end of the armbody; and a third axis having one end, which is connected to another endof the second axis, and another end, which is connected to the gripper,wherein the FT sensor is disposed between the gripper and the thirdaxis, and wherein the neighboring sensor is disposed on a front surfaceof the arm body.
 9. The method of claim 8, wherein, in the step ofmoving the bumper, a position of the gripper is controlled in athree-dimensional space by operating the multi-axis arm by using a motorand a decelerating gear, wherein in the step of detecting the directionof the external force, a reference rotation position and an actualrotation position of the motor are detected and according to adifference between the reference rotation position and the actualrotation position it is determined whether a collision occurs, and whenit is determined that the collision is occurred, the motor stopsoperating.
 10. The method of claim 8, further comprising: decreasing arotational torque that is applied a robot body of the cooperation robotby the multi-axis arm by moving a weight toward or away from the robotbody, the weight is disposed on opposite side of the multi-axis arm onthe basis of the robot body according to upper and lower position of themulti-axis arm, wherein the gripper is mounted on a front end portion ofthe multi-axis arm and the robot body is disposed on a rear end portionof the multi-axis arm.
 11. The method of claim 8, wherein the FT sensoris disposed on a part connecting the multi-axis arm and the gripper.